Show information about the number of selected rows and columns

Description

Please, add an option to show information about the number of selected rows and columns. This is how it looks in LO Calc:

Labplot Version

Debug build 
System: Ubuntu 23.04
Locale: English,United States (Decimal point ',', Group separator ' '
Number settings: Decimal point ',', Group separator ' ', Exponential 'e', Zero digit '0', Percent '%', Positive/Negative sign '+'/'-' (Updated on restart)
Architecture: x86_64-little_endian-lp64
Kernel: linux 6.2.0-27-generic
C++ Compiler: GNU 12.3.0
C++ Compiler Flags: -g -O2 -fdebug-prefix-map=/build/labplot-T02dtW/labplot-2.10.1+git202308110632~ubuntu23.04.1=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fno-operator-names -fno-exceptions -Wall -Wextra -Wcast-align -Wchar-subscripts -Wformat-security -Wno-long-long -Wpointer-arith -Wundef -Wnon-virtual-dtor -Woverloaded-virtual -Werror=return-type -Werror=init-self -Wvla -Wdate-time -Wsuggest-override -Wlogical-op -Wall -Wextra -Wundef -Wpointer-arith -Wunreachable-code -Wunused -Wdeprecated-declarations -fno-omit-frame-pointer -fstack-protector -fexceptions -std=c++17 -O2 -Wcast-align -Wswitch-enum -fvisibility=default -pedantic -Wzero-as-null-pointer-constant